Question

question 19
4 pts

1. crossing over occurs during which stage of meiosis?

o anaphase ii
o mataphase i
o prophase i
o telophase i

Explanation:

Crossing - over is a key event in meiosis. It involves the exchange of genetic material between homologous chromosomes. In meiosis, prophase I has several sub - stages (leptotene, zygotene, pachytene, diplotene, diakinesis). During pachytene (a part of prophase I), homologous chromosomes pair up closely (synapsis) and crossing - over (exchange of genetic segments) occurs.
Anaphase II is about the separation of sister chromatids. Metaphase I is when homologous chromosomes align at the equatorial plate. Telophase I is the stage of chromosome de - condensation and nuclear envelope re - formation at the end of meiosis I.

Answer:

Prophase I